JsFooterPlugin sets Http Response content empty if PCRE limit reached

[cundd]

Preconditions (*)

1. Magento 2.3.2-p2
2. PHP 7.1
3. pcre.backtrack_limit = 1000000 (Default)
4. pcre.recursion_limit = 1000000 (Default)
5. dev/js/move_script_to_bottom=enabled

Steps to reproduce (*)

1. Build a huge HTML output (e.g. shopping cart with a lot of complex products)

Expected result (*)

1. Output should be turned or error should be thrown

Actual result (*)

1. A HTTP status code 200 without a response body is returned

The call to preg_replace_callback() in JsFooterPlugin will fail silently, resulting in a blank page. The reason for this is, that preg_replace_callback() will return NULL if one of it's limits is reached. NULL will further be used to set the content of the HTTP response.

A first step would be to check if the result of preg_replace_callback() is NULL and throw an appropriate exception (generated from preg_last_error()).

[m2-assistant]

Hi @cundd. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

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• Information on your environment
• Steps to reproduce
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Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento give me 2.4-develop instance - upcoming 2.4.x release

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@cundd do you confirm that you were able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• yes
• no

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[cundd]

@magento give me 2.4-develop instance

[magento-engcom-team]

Hi @cundd. Thank you for your request. I'm working on Magento 2.4-develop instance for you

[magento-engcom-team]

Hi @cundd, here is your Magento instance.
Admin access: https://i-26026-2-4-develop.instances.magento-community.engineering/admin
Login: admin Password: 123123q
Instance will be terminated in up to 3 hours.

[cundd]

I couldn't manage to reproduce it with the admin access only, but fixing this would more be a general improvement to the Magento framework, rather than an immediate fix for a bug.

[m2-assistant]

Hi @engcom-Echo. Thank you for working on this issue.
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[magento-engcom-team]

✅ Confirmed by @engcom-Echo
Thank you for verifying the issue. Based on the provided information internal tickets MC-29768 were created

Issue Available: @engcom-Echo, You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself.